Wars between Persia and Greece, 499–479 B.C.E.

The Athenian ambassadors in 507 B.C.E. agreed to the Persian requirement for an alliance: presenting tokens of earth and water to acknowledge submission to the Persian king. However, the Athenian assembly failed to inform King Darius that it had rejected his terms; he continued to believe that Athens had agreed to obey him in return for support. This misunderstanding planted the seed for two Persian attacks on Greece. Since the Persian Empire far outweighed the Greek city-states in soldiers and money, the conflict pitted the equivalent of a huge bear against a pack of undersized dogs.